Tesla did great work with AC generators and motors. Most common AC motors today still use approaches he invented. That's his legacy.

Wardenclyffe, though, is a monument to failure. From his patents, you can read how he thought it would work. He thought the ionosphere was a conductive layer. The Wardenclyffe tower was supposed to punch power through the atmosphere to that conductive layer, so that signals and maybe power could be received elsewhere.

The ionosphere does not work that way. Tesla's tower would have done nothing useful, although with 200KW at 20KHz going in, it probably could have lit up fluorescent lamps and gas tubes for some distance around. Since the location is now surrounded by a housing subdivision, rebuilding the tower and powering it up would annoy the neighbors.